The invention relates to the art of mowing and mowing apparatus. The invention finds particular application in conjunction with boom mowers and will be described in particular reference thereto.
Heretofore, mowing apparatus have been connected with tractors in various manners. Articulated boom assemblies have been found to be particularly advantageous for supporting mowing apparatus on tractors. The boom assembly included a plurality of arms, a first of which was pivotally connected with a tractor and a second of which was pivotally connected between the mowing apparatus and the first arm. Hydraulic cylinders were provided to control the angular orientation of the first arm relative to the tractor and the second arm relative to the first. This enabled the boom assembly to reach over guardrails and other structures to position the mowing apparatus. It was further necessary to control the angular orientation of the mowing apparatus relative to the second boom arm such that it conformed with the desired mowing pitch.
To control the orientation of the mowing apparatus, a toothed gear was rigidly mounted to the mowing apparatus with its axis through the pivot which connects the mowing apparatus and the second arm. A second tooth gear was mounted freewheeling on the second arm and a flexible chain extended around the two gears. By moving the chain, the angular orientation of the mowing apparatus was readily selectable. To control the positioning of the chain, a hydraulic cylinder was connected at one end with the second arm and at its other end with the chain. By extending and contracting the hydraulic cylinder, the chain could be moved in either direction and the angular orientation of the mowing apparatus controlled.
Although the chain drive angular orientation control mechanism has been successful, it has had drawbacks. For example, the chain drive tended to become fouled with debris. Frequent maintenance to clean the chain and check for wear were commonly required. Further, the drive chain was apt to break under severe conditions.
The present invention contemplates a new and improved angular orientation control mechanism for mowing apparatus which overcomes the above referenced problems and others. The present invention accommodates adverse bank or ravine conditions as well as various orientations or degrees of extension of the boom arms. The mowing apparatus angular orientation control mechanism is able to control the orientation of the mowing apparatus over a range of about 180.degree..